System for erecting multistorey buildings

ABSTRACT

A slab lifting jack assembly system associated with a vertical H-beam having a row of aligned vertical openings on each side of each flange of the beam with the jack assembly having an upper set of pins movable by hydraulic cylinder means into and out of engagement with the openings in the flanges and a lower set of pins similarly movable with a main hydraulic cylinder connected between an upper frame supporting the upper pins and a lower frame supporting the lower pins with the upper frame also being connected to a concrete slab so that extension of the hydraulic cylinder serves to lift the slab when the upper pins are retracted out of engagement with the flange openings and the lower pins are extended to remain in the flange openings so that the slab is consequently lifted by extension of the frame cylinder and with control means including logic circuitry for detecting and preventing malfunctions of the system.

United States Patent 3,008,691 11/1961 Steele et a1. 254/106 3,028,143 52/126X 254/106 [72] Inventors James L. Regan (409 Dunkel St.,

Fairbanks, Alaska, 99701); 4/ 1962 Cheskin..... David L. Gamhart, Hayward, Calif. 3,389,890 6/1968 Bradburymm................ 1968 Primary Examiner-Price C. Faw, Jr.

9 Patemed y 1971 Attorney Mason, Fenwick and Lawrence [73] Assignee assignor to said Regan by said Garnhart ABSTRACT: A slab lifting jack assembly system associated [54] SYSTEM FOR ERECTING MULTISTOREY with a vertical H-beam having a row of aligned vertical openings on each side of each flange of the beam with the jack assembly having an upper set of pins movable by hydraulic cylinder means into and out of engagement with the openings in the flanges and a lower set of pins similarly movable with a main hydraulic cylinder connected between an upper frame BUILDINGS 25 Claims, 21 Drawing Figs.

supporting the upper pins and a lower frame supporting the lower pins with the upper frame also being connected to a 122,115, 745; 254/106, 93, 89 (H),

concrete slab so that extension of the hydraulic cylinder serves to lift the slab when the upper pins are retracted out of en- [56] References Cited UNITED STATES PATENTS 2,540,679 2/1951 gagement with the flange openings and the lower pins are ex- Laffaille....................... 2,932,486 4/1960 Suderow...,...........

7/1961 Rasmussenetal............

PATENTEU HAY 2 5 IBYI SHEET 03 0F 10 PATENTEU umzsmn 3.579.935

SHEET on HF 10 LOWER PINS INVENTOR \OB IS JAME-s L. Ream:

a; [3mm L. GARNHART mi: wu;

ATTORNEYS PATENTEU W25 l97l sum 0? nr 10 SYSTEM FOR ERECTING MULTISTOREY BUILDINGS BACKGROUND OF THE INVENTION This invention relates to the field of devices for constructing buildings or similar constructions and is specifically directed to a building device for lifting a prepoured concrete slab upwardly along conventional vertical columns to a final position.

Many devices have been proposed in the past for the purpose of erecting a multistoried concrete building by the pouring of all of the slabs at ground level in a stacked manner with respect to each other. The slabs are then subsequently lifted to their upper floorpositions by such devices for final positioning. This construction method is generally referred to as liftslab construction and a wide variety of devices have been employed in its practice.

Unfortunately, all of the previously known devices have suffered from one or more serious defects such as high cost, complexity, unreliability and functional limitations.

For example, many of the previously known devices are limited in that they must be attached to the top of a vertical beam to extend downwardly a substantial distance to lift one or more slabs stacked at ground level. A device of this sort is exemplified by US. Pat. No. 2,720,017. The number of slabs that can be lifted by devices of this sort is quite limited and consequently only small buildings can be fabricated by the use of such a device.

Another form of slab lifting construction employing lifting means mounted above the slab being lifted is illustrated in US. Pat. No. 3,065,573. The device illustrated in this patent employs a hydraulic cylinder means movable upward above the slab being lifted and connected to the slab by means of a plurality of flexible cables. Devices of this sort are also limited in that they can only lift a relatively few slabs so that the building construction possible is limited as to height. Moreover, devices of this sort require an extended length of vertical beam above the final position of the slab being lifted due to the necessity for supporting the lifting mechanism above the slab.

Another disadvantage of the previously known devices is that they have universally failed to provide adequate control and sensor means for preventing and detecting accidents and malfunctions while such are correctable.

Various other systems such as the system illustrated in US. Pat. No. 3,028,707 have been employed for lifting prepoured slabs; however, none of the previous devices have won widespread acceptance due to their above-discussed limitatrons.

SUMMARY OF THE INVENTION Therefore, it is a primary object of this invention to provide a new and improved system for lifting prepoured slabs upward along vertical beams for final positioning.

Obtainment of the object of this invention is enabled by the provision of a jack assembly connected to each slab at each vertical beam. Each jack assembly includes a pair of main hydraulic piston and cylinder assemblies respectively mounted on each side of the beam. The upper end and the lower end of each piston and cylinder assembly is provided with a support frame encircling the beam and supporting a pair of small hydraulic cylinders each having support pins attached to the outer end of the piston rod.

Each flange of the beam is provided with a vertical row of openings which are positioned for receiving the respective support pins when their individual hydraulic cylinders are actuated to extend the pins into the respective openings. When the individual hydraulic cylinders are actuated to retract the pins, the ends of the pins move to a position within the confines of the inner sides of the flanges of the beams. When the lowermost pins are extended into the openings in the beam, the upper pins can be retracted and the main vertical hydraulic cylinders actuated to lift the upper frame assembly upwardly. When the upper frame assembly reaches its upper extent of movement, the upper pins are extended to be received in the holes in the beam and the lower pins are retracted. The main vertical hydraulic cylinders are then actuated to lift the lower frame upwardly in a contracting manner so that the lower pins can be inserted in a higher pair of beam openings and the cycle repeated so that the entire system works its way up the beam. An additional feature of this invention resides in a plurality of sensors for detecting the positions of the pins, cylinders and the like and control logic means for preventing actuation of the system in case of the detection of a malfunction. Moreover, the system provides for the automatic determination of a predetermined final slab position and the deenergization of the system upon the arrival of a slab being lifted at the predetermined point along the beam.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial perspective view illustrating a building being constructed by the apparatus of this invention;

FIG. 2 is a sectional view taken long lines 2-2 of FIG. 1;

FIG. 3 is a sectional view taken along lines 3-3 of FIG. 2;

FIG. 4 is a sectional view taken along lines 4-4 of FIG. 3;

FIG. 5 is a sectional view taken along lines 5-5 of FIG. 4;

FIG. 6 is a sectional view taken along lines 6-6 of FIG. 4;

FIG. 7 is a sectional view taken along lines 7-7 of FIG 4;

FIG. 8 is an exploded perspective view of the elements of a jack assembly portion of the preferred embodiment;

FIG. 9 is a schematic illustration of hydraulic means employed in the invention; I

FIG. 10 is an elevational view illustrating the method by which the respective floor slabs are permanently positioned;

FIG. 11 is a sectional view taken along lines 10-10 of FIG. 10;

FIG. 12 is a sectional view taken along lines ll-ll of FIG. 1 1;

FIG. 13 is a plan illustration of a portion of the control tape employed in the preferred embodiment of the invention for controlling the movement of the slabs;

FIG. 14 is a schematic illustration of control logic means associated in a main control console for controlling jack units associated with the various slabs to be controlled with the connections to one slab and between jack units of the slab also being illustrated;

FIG. 15 is a schematic illustration of a portion of the logic circuitry employed with each jack unit;

FIG. 16 is a schematic illustration of another portion of the logic circuitry employed with each jack unit;

FIG. 17 is a schematic illustration of yet another portion of the logic circuitry employed with each jack unit;

FIG. 18 illustrates another portion of the logic circuitry employed with each jack unit;

FIG. 19 is a circuit diagram of another portion of the logic circuitry employed with each jack unit;

FIG. 20 is a timing chart illustrating a normal run of the device in a lifting mode of operation; and

FIG. 21 is a timing chart illustrating a jack recycling operation during a cycle of operation of the system.

DESCRIPTION OF THE PREFERRED EMBODIMENT Attention is initially invited to FIG. 1 of the drawings which symbolically illustrates the manner in which the preferred embodiment of this invention is employed in the construction of a building.

The initial step in the employment of this invention is the pouring of a foundation 20 having a plurality of vertically extending beams or columns 22 which are in the form of H- beams. A plurality of stacked concrete slabs 24 are then poured in place on the top of the foundation 20. Each slab is separated from adjacent slabs and the lower slab is separated from the foundation by the use of a plastic film, liquid coating or any other conventional means for separating adjacent poured concrete constructions so that the separate slabs may be separated to be moved along the vertical columns by the lifting system forming the subject matter of this invention. The

manner in which the slabs are made separable forms no part of this invention, and any one of many numerous conventional procedures may be employed for this purpose.

Each slab is poured about a metal lift ring assembly 26 which provides an open space encircling each of the vertical columns and having sufficient interior dimensions to accommodate a jack assembly on its interior. The lower portion of each ring 26 is defined by a conical lift surface 27, the purpose of which will be discussed hereinafter. A separate jack assembly is associated with each lift ring 26 so that in the example illustrated in FIG. 1, a total of six jack assemblies would be associated with each slab. It should be understood that the construction illustrated in FIG. 1 is merelyexemplary and that slabs of any shape having more or less vertical columns than those shown could be employed in the practice of this invention.

Each jack assembly is provided with its own hydraulic pump and electric motor and power lines and control wires are connected to each jack assembly prior to the pouring of the respective slabs. A central control console is connected to the power lines and control wires so that each jack can be controlled from the central location. The details of construction of each jack and the control assembly is discussed hereinafter; however, the wires and cables leading to each jack assembly are not illustrated in the drawings in order to avoid an undue and unnecessary cluttering of such.

Actuation of the jack assemblies for any particular slab causes that slab to be lifted upwardly along columns 22. Either a single slab or a plurality of slabs may be moved at any one time and extensions 28 can be welded to the tops of the respective vertical columns 22 as the building progresses upwardly. Also, exterior panelling 30 can be added to the slabs after achieving the required vertical separation between the slabs which are then subsequently moved upwardly as a unit.

Each of the H-beams 22 is of special construction in that each flange 32 is provided with a vertical series of openings 34 on opposite sides of web 36 of the beam. The openings in each series are in vertical alignment as shown in FIGS. 1 and 2 and are also in respective horizontal alignment with each other. These openings provide means for engaging the beam by the respective jack means for lifting of the slab upwardly along the respective beams.

Turning now to FIGS. 3-8, the construction of each jack assembly will be discussed in detail. Each jack assembly includes an upper lifting frame generally designated 40 and a lower lifting frame generally designated 42 as shown in FIGS. 4 and 5. A pair of expandable and contractable hydraulic piston and cylinder assemblies 44 connect the upper lifting frame and the lower lifting frame for relative movement with respect to each other.

Each upper lifting frame 40 is of identical construction and includes a pair of identical primary lift plates 46 formed of a horizontal plate 48 and a vertical plate 50 connected in perpendicular relationship with respect to each other (FIGS. 4 and 8). Each horizontal plate 48 is provided with a strengthening rib 51 attached to its upper surface immediately above a threaded aperture 51 which receives the threaded end 54 of a piston 56 of the piston and cylinder assembly 44. Each of the horizontal plates 48 is also provided with a pair of laterally extending ear portions 58 which extend outwardly beyond the flanges 32 of the associated beam 22 as shown in FIG. 3. Moreover, each horizontal plate 48 has a main body portion 60 extending inwardly between flanges 32 as shown in FIG. 3. Vertical plate 50 is connected to the edge of a main body portion 60 of each lift plate closest to web 36 as shown in FIG. 4. A lifting frame gusset 62 extends vertically downwardly from the lower surface of horizontal plate 48 immediately beneath the innermost edges of cars 58 and rib 51 as shown in FIG. 8. The outer edge of each gusset 62 is provided with a notch or opening provided by a transversely extending support lug 64. Each of the'lugs 64 provides support for one end of an upper lift bar 66 which extends alongside the outer surface of each flange 32 of beam 22 between each of the horizontal plates 48 of each jack assembly. The ends of the respective upper lift bars 66 are curved inward at 67 to conform with the curved outer edge of the ears 58 under which they are adjacently as sociated as clearly illustrated in FIG. 8. Two pin receiving apertures 68 are formed in each upper lift bar 66 and are alignable with the openings 34 of the beam with which the jack assembly is employed. Apertures 68 and openings 34 are of equal and identical size and shape.

A connection between the upper lifting frame 40 and lift ring assembly 26 is provided by four lifting lug members 70 having a curved body portion 72 extending vertically between an upper cap lug 74 and a lower base lug 76. Each cap lug 74 extends inwardly over the top surface of horizontal plate 48 in the portions formed by the four cars 58 of the assembly and the inner surface of each curved body portion conforms with the curved edge of ears 58 and the curved ends 67 of lift bars 66 as shown in the drawings.

A curved lift block 78 is positioned between the lifting lug member 70 and the inner surface 80 of lift ring assembly 26. A curved tapered wedge 82 is forcefully driven between base lug 76, curved body portion 72 and lift lug 78 as shown in FIG. 4 to maintain the respective parts in their illustrated positions. Wedge 82 forcefully biases the lift blocks against surface 80 of the lift ring 26 so that any vertical movement of the upper lifting frame 40 will immediately be transmitted to the slab.

Lower lifting frame 42 comprises a pair of cylinder support plates 82 (FIG. 6) located on opposite sides of each beam and having an inwardly extending plate portion 84 extending inwardly between the flanges of the beam and terminating in a vertical pin support plate 86. A pair of aligned vertical plates 88 extend upwardly from cylinder support plate 82 exteriorly of the ends of flanges 32 as shown in FIG. 6. The space between the vertical plates 88 is occupied by the piston and cylinder assembly 44 and the end of the plates 88 are welded to the cylinder as shown in FIG. 6. Each of the outer ends of vertical plates 88 is provided with two apertures for receiving bolts 89 for connecting a lower lift bar 90 extending between vertical plates 88 on each side of the beam as illustrated in FIG. 6. A gusset 91 extends beneath the bolted joint of elements 88 and 90. Each of the lower lift bars 90 is provided with a pair of pin receiving apertures which are alignable with the apertures 34 in the flanges of beams 22.

A vertical cylinder support bracket plate 102 extends perpendicularly outwardly from the central portion of each of the cylinder support plates 82 and supports two pin cylinder assemblies 104. Each pin cylinder assembly comprises a hydraulic cylinder having a movable piston with an extendable piston rod 106 which has an offset pin 108 on its outermost end. Each of the pins 108 is offset so that the two pins on one side of the web are in axial alignment with each other so as to be insertable in the aligned apertures 34 in flanges 32.

Similarly, the upper lift frame 40 is provided with two pairs of pin cylinder assemblies 110 attached to an upper cylinder support bracket plate 114 extending outwardly from a central portion of vertical plate 50 as illustrated in FIG. 7. Each pin cylinder assembly 110 is provided with offset support pins 116 attached to the end of the piston rod of each assembly in the exact same manner as the lower pin cylinder assembly so that the support pins on one side of the web are coaxial for movement into the openings 34 in the flanges 32.

The upper pins 116 are movable between an extended position in which the pins extend through their associated flanges 32 and openings 68 in upper lift bar 66 and a retracted position wherein the pins are located entirely within the confines of the space between flanges 32. The extended position of the upper pins is illustrated by the uppermost set of pins 116 in FIG. 5 whereas the retracted position of the upper pins is illustrated by the upper pins associated with the middle slab in FIG. 5.

In a like manner, the lower pins 108 are movable between an extended position extending through the associated flange 32 and the associated lower lift bars 90 and a retracted position entirely within the confines of flanges 32. The extended position of the lower pins 108 is illustrated by the lower pins associated with the middle slab illustrated in FIG. 5. Similarly, the retracted position of the lower pins is illustrated by the position of the lower pins associated with the upper slab of FIG. 5.

The hydraulic system for each jack assembly is self-contained and is entirely independent from the hydraulic systems of the other assemblies.

Each individual hydraulic system is connected as shown in FIG. 9 and includes an electric motor 120 driving a hydraulic pump 122 which receives hydraulic fluid from a reservoir 124. The output 126 of the pump is provided with a pressure release valve 128 for directing excess fluid back to a reservoir 124.

Output line 126 is connected to an upper pin electromagnetic control valve 130 which is movable between first and second positions for extending or retracting the upper pins 116 as illustrated in FIG. 9 of the drawings. Activation of the coil or valve 130 is caused by a signal to a valve activator 131 to move the valve to cause hydraulic fluid to be directed to move pins 116 inwardly and a similar electromagnetic valve 132 is controlled by a signal to a valve activator circuit means 133 to control the lower pins 108 in the same manner. A lift jack control valve 134 is positionable to cause the hydraulic piston and cylinder'assembly 44 to liftingly move to an extended upward position or loweringly move to a retracted lower position. Energization of coil 137 operates the valve 134 to cause a lifting (extending) action of jack 44 whereas activation of coil 135 activates valve 134 to cause a lowering (contracting) action of jack 44.

Turning now to FIGS. 4 and 5, the manner in which each jack assembly is operated for raising the slab will be discussed. A lifting operation is begun with the lower pin cylinders being actuated so that the lower pins 108 are in the position illustrated by the pins 108 associated with the middle slab (FIG. 5). The upper pins are in their retracted position and the hydraulic piston and cylinder assembly 44 is initially contracted as illustrated by the assembly 44 of the middle slab of FIG. 5. Assembly 44 is then actuated to move the slab upwardly. Complete extension of assemblies 44 positions the upper pins 116 in exact alignment with the next pair of openings 34 immediately above the pair of openings that the pins were adjacent at the beginning of the lifting cycle. The upper pins are then extended to pass through the adjacent openings 34 in the flanges 32 and the apertures 68 of the upper lift bars 66. Valve 132 is then actuated to retract the lower pins 108 so that actuation of the lift jack control valve 134 to retract (contract) hydraulic piston and cylinder assembly 44 serves to lift the lower frame assembly upwardly into adjacent relationship with the upper frame assembly. The lower pins are then extended and the upper pins are retracted to assume the position shown by the middle slab and the jack assembly is consequently ready for the next cycle or increment of lifting movement.

All of these jacks associated with any particular slab must be activated at any one time and the jacks associated with a plurality of slabs can be activated at any one time after a sufiicient spacing between the adjacent slabs has been obtained. The means for controlling actuation of the respective means is discussed in detail hereinafter.

When a slab has been lifted to its final position, it is necessary to permanently connect the slab to the associated beams to complete the construction. The manner in which this is accomplished is illustrated in FIGS. 10, 11 and 12 and reference is made thereto.

The initial step in providing for a permanent balljoint connection consists in the positioning of a seating ring 136 in abutting relationship with a fiber cushion 138 engaging the conical lift and supporting surface 27 of lift ring assembly 26. A pair of anchor plates 140 are bolted to flanges 32 as shown in FIGS. 9 and 10. Each anchor plate 140 has two beveled comer surfaces 142 facing conical surface 27 as shown. A threaded support rod 144 is welded to each corner surface 142 as shown in detail in FIG. 11 and an adjusting net 146 is threaded thereon. A support sleeve 148 engages adjusting nut 146 on one end and engages seating ring 136 on its upper end as illustrated. Sleeve 148 embraces a positioning pin extending outwardly from seating ring 136.

Adjusting nut 146 is adjusted to forcefully urge sleeve 148 upward against the resistance of the seating ring and slab for all four of the final support assemblies associated with the given beam. The jack assembly is then removed and the slab is supported in each beam by the four support assemblies. A concrete column 162 (FIG. 10) is then poured about the entire assembly to provide a permanent construction. The column 162 can be round, square or any other desired shape.

Control and actuation of the respective jack assemblies associated with each beam and each slab and is enabled by the provision of a plurality of sensors and detecting means for detecting the position of the main lift jack assembly and pins 108 and 116. Specifically, movement of the upper pins 106 to their extended position isdetected by a pair of microswitches and 170 which are respectively engaged by the radial extension of the plate which supported pins 116 as shown in FIG. 5 so that closure of these switches provides a signal TPO indicative that the top pins are out. Similarly, the movement of pins 116 to their retracted position serves to close the contacts of a pair of retracted position detecting microswitches 172 and 172 to give a top pins retracted signal TPR.

The pair of microswitches and 175 similarly detect the extended position of lower pins 108 to give a BPO (bottom pins out) signal that the bottom pins are retracted in the column whereas a pair of inwardly mounted microswitches 173 and 173 give a BPR (bottom pins retracted) signal indicative that the bottom pins are in their retracted position. Similarly, closure of the switches 170 and 170 provides a TPO (top pins out) signal whereas closure of switches 172 and 172 gives a TPR (top pins retracted) signal.

It is necessary at all times to accurately maintain knowledge of the distance between adjacentslabs in order to properly control the system. Obtainment of this result is enabled by the provision of a counter 274 which counts the steps or increments of travel up or down by the moving slabs. By counting to a preset count, the system is stopped when the desired distance exists between the slab still on the ground and the last one to be activated. All moving slabs are maintained fixed distances apart by the fact that they must move each increment together or the system receives a fail indication and travel is stopped.

It is also necessary to accurately know the extended distance of each jack and their position relative to the punched holes in the H-beam. Obtainment of this result is enabled by the provision of a steel tape 174 (FIG. 13) having one end adjustably attached to the lower edge of vertical plate 50 as shown in FIG. 5 and having its other end received in a spring recoil reel assembly 176 attached adjacent the upper edge of the vertical plate 86. Tape 174 is maintained in a constanttensioned condition and is provided with a plurality of apertures arranged in three vertical rows or columns A, B and C as shown in FIG. 13.

Tape 174 extends through a photocell readout assembly 178 which has a photocell detector associated with each of the vertical rows of holes A, B and C for detection of the openings in the tape. However, a plurality of microswitch assemblies could be employed for detecting the openings in vertical rows A, B and C if such should be desired. The photocells associated with each column provide signals PCA, PCB and FCC when holes in columns A, B and C are respectively individually detected.

A hole in Column A is adjacent the photocell readout means when the twoadjacent slabs are in their initial positions, with the upper slab resting upon the lower slab. The tape 174 is punched so that separating movement of the slabs initially presents a hole in column B, then a hole in column C, then a hole in column A, etc. to the respective photocells as the slabs move apart. Distance h required to be moved to present the next hole is designated in FIG. 13 and is normally one-eighth of an inch. In operation, all of the jacks associated with a given slab would be actuated to move the one-eighth of an inch increment. When all jacks have completed the increment of movement, they would then be actuated to make the next increment of movement until, after a plurality of incremental movements, the slabs would have been separated or moved a distance equal to the maximum stroke of the lifting cylinder or the complete distance of movement desired. When the slabs reach the extent of movement possible for the cylinder, all three of columns A, B and C are provided with aligned holes and these holes are simultaneously detected by the three photocell readout means in element 178.

Each jack assembly associated with each slab at each beam includes two jack units with each jack unit consisting of the lifting cylinder assembly 44 on each side of the web of the beam.

Centralized control of the movement of the slabs is provided from a main control console 200 (FIG. 14) normally located at ground level and connected to each slab by control cables embedded in the slab when the slab is poured. The control cables are connected to each jack unit for detecting the condition of each jack unit and providing overall control of the actuation of the elements of each jack unit. Each jack unit is provided with its own individual detection and control circuitry and this circuitry can be located with the jack unit or in the main control panel or can be partially located in both locations in accordance with the nature of the particular construction being performed.

FIG. 14 symbolically illustrates the manner in which the main control console 200 is connected to a slab having four jack units. Power to drive the electrical components such as the pumps 122 is provided by a power cable 202 which is connected to each jack unit of the slab and a common cable 204 which is similarly connected to each jack of the slab. A lift mode signal cable 206 and a lower mode signal cable 208 are also connected between the console and each jack unit for providing lift signals and lower signals in accordance with the function to be performed. While two control signal cables 206 and 208 are illustrated, it would be possible to use a signal control cable receiving signals at different levels indicative of either a lift or lower function with a discriminator circuit being provided adjacent the jack for determining the nature of the signal and actuating the jack accordingly. Moreover, a go" signal power line 210 is connected between the main control console and each jack of the particular slab. Line 210 is connected to the contacts of a jack unit go relay in each relay in a series circuit which terminates at the last jack unit in the circuit which is connected to a go" indicator return signal line 212. Activation of each go" relay in each jack unit of a particular slab serves to complete the circuit from line 210 through each jack unit and returned by line 202 and master AND gate 214 in the main console.

Each input of the master AND gate 214 is connected to a respective go" indicator return signal line 212 of a different slab. It is necessary that a signal be received by all of the inputs of the master AND gate before an output signal 215 indicating that all slabs are go" will be provided from the gate. However, in some instances, it will be immaterial whether or not slabs which are not to be moved are in condition for movement and it will therefore be desirable to provide an artificial go signal to the master AND gate from the stationary slabs in order to move those slabs that are desired to be moved. In such an instance, the circuit between the go power lines 210 and the return line 212 for those particular slabs which are not desired to be moved would be made by closure of an override switch 216 connected between the go power line and the go return signal line 212 as shown in FIG. 14. Switch 216 would also be used for providing an artificial go" signal from any outputs not actually connected to a slab. Under such conditions, it would then only be necessary to receive a valid go" signal from those slabs to be moved so as to provide an output signal 215 from the master gate 214. Moreover, the deactivation or activation of any particular slab could be controlled by a master slab relay for connecting lines 206, 208, 202 and 204 to the particular slab desired to be activated with switch 216 being controlled by the same relay. Therefore, activation of the master slab relay switch to deactivate a slab would automatically disconnect all power to the slab while simultaneously closing switch contacts 216. Master switches for the slabs are not shown in the drawings. Each of the go" indicator signal lines connected to master gate 214 is also connected to an indicator circuit including an amplifier 218 and an input indicator lamp 220 which is activated upon the receipt of a go signal for its particular slab as will be obvious from inspection of FIG. 14. Moreover, an inverter 222 is connected to each go" signal line 212 to provide a signal which is amplified by amplifier 230 and is indicative of failure to receive a go signal and consequently provides a fail signal 232. Fail signal 232 activates a fail indicator lamp 234 to give an indication at the console that the particular slab is in a no-go or fail condition.

Console 200 also includes a lift initiating master switch 236 which has one terminal connected to a signal power source 238 and its other terminal connected to one control input of a lift mode flip-flop 239. A lift stop OR gate 240 has its output 242 connected to the other control input of a lifting mode flipflop 239. Lift stop OR gate 240 is activated by receipt of either a system stop signal 244, a stop signal 246 or a lower mode signal 248 from various sources to be discussed hereinafter. Closure of switch 246 causes flip-flop 239 to provide a lift mode signal 250 whereas receipt of an output signal 242 from a flip-flop OR gate 240 causes flip-flop 239 to provide a signal 252 indicative of the absence of a lift mode signal.

Similarly, console 200 is provided with a lowering operation initiating master switch 256 which has one terminal connected to the signal power source 238 and its other terminal connected to one control input of a lowering mode flip-flop 258. The other input of the lowering mode flip-flop 258 is connected to a lowering stop OR gate 260. The output of lowering stop OR gate 260 is initiated by receipt of a system stop signal 244, a stop signal 246 or a lift mode signal 250.

A lift output signal providing AND gate 264 has its output connected to line 206 whereas a lower output signal providing AND gate 266 has its output connected to line 208 so as to provide signals to the respective slabs. One input of AND gate 264 is connected to receive a lift mode signal 250 and a signal 268 indicative that the all go signal 215 from gate 214 has been dropped by virtue of its operational steps to be discussed hereinafter. It should be noted that the signal 268 is a stable signal from a delay multivibrator 270 which also provides a step completed signal 272 upon receipt of an all go signal 215.

The control console 200 also includes a settable counter 274 which can have any desired final preset count inserted into its memory circuitry so that when the counter 274 reaches the final preset count, a system stop signal 278 is provided by counter 274. Counter 274 is reset to a zero condition by a reset AND gate 280 which is operative upon the simultaneous actuation of a manual reset switch 282 and the concurrent receipt of a signal 252 indicative of the absence of a lift mode of operation and a signal 286 from flip-flop 258 indicative of the absence of a lower mode of operation. Moreover, counter 274 receives count signals either from a count up AND gate 300 or a count down AND gate 302. Both of the gates 300 and 302 are connected to receive a step completed signal 272 and the gate 300 is connected to receive a lift mode signal 250 while the gate 302 is connected to receive a lower mode signal 248. Consequently, a count up is added to the counter upon the simultaneous receipt of a lift mode signal 250 and a step completed signal whereas a count down signal is received upon the simultaneous receipt of a lower mode signal 248 and a step completed signal. Counter 274 also includes an indicator 251 which is activated when the counter has a count greater than zero.

The control console 200 is also provided with a stop switch 304 which, when activated, controls a flip-flop 306 for providing a stop signal 246 for deactivating the entire system.

FIG. illustrates the logic and control elements associated with each jack assembly and which is connected to the main control console. As was noted previously, each jack assembly is connected to a lift mode signal providing cable 206 and a lower rnode signal providing cable 208 which cables provide the instructions for direction of movement of the unit. Moreover, each jack unit is also connected to power line 202 and the line 204. Similarly, the last unit is connected to a go signal line 210 which is connected to one contact of the relay contacts 310 ofthe go relay 312 (FIG. 17).

Sensor means associated with the various elements of each jack unit includes a pump pressure detecting switch 320 which provides a pressure signal 321 indicative of the fact that the pump pressure in the output line 126 from the pump is at an adequate level; moreover, an inverter 322 provides a signal 323 indicative of the absence of adequate hydraulic pressure. An AND gate 330 provides a signal TPR indicative that the top pins 116 have been retracted. The TPR signal is provided in response to the closure of switches 172 and 172 and another AND gate 332 provides a signal 'IPO indicative of the fact that the top pins 116 are out or extended as indicated by the closure of switches 170 and 170. Similarly, an AND gate 334 provides a signal BPR (bottom pins retracted) in response to the closure of switches 173 and 173' indicative that the bottom pins are retracted; whereas, another AND gate 336 provides a signal BPO indicative of the fact that the bottom pins are out (extended as evidenced by the closure of switches 175 and 175". The jack bottom switch 339, when closed, provides a bottom signal 338 and an inverter 340 provides a signal 342 indicative of the absence of a bottom signal 338.

A lift signal from cable 206 enters the jack unit for actuating a mode indicating flip-flop 346 to provide a lifting mode signal 348. A lower signal from cable 208, on the other hand, causes mode indicating flip-flop 346 to provide a lowering signal 350. Moreover, a lift signal on cable 206 activates a jack unit OR gate 352 to provide a unit lift signal 353. Similarly, a manual jack unit control button 354, when closed, directs a signal to flip-flop 356 which gives an output signal 358 which will also provide a unit lift signal 353 from OR gate 352 in an obvious manner. The unit lift signal 353 triggers a unit start OR gate 360 whose output triggers first and second delay multivibrators 362 and 364. The output from multivibrator 362 is directed to an AND gate 366 which initiates a timer signal 368 when applied to the gate simultaneously with a signal 370 indicative of the absence of a hold signal. Delay multivibrator 364, on the other hand, provides a start signal 372 at the required time in relationship to the other circuit elements.

The application of a system lower signal by cable 208 activates a second unit OR gate 374, the output of which provides a unit lower signal 376. A manual lower button 378 is connected to a flip-flop 380 for providing a unit lowering signal in the same manner as the previously discussed manual lift switch 354 and flip-flop 356 provides a manual lift signal. It should also be noted that jack unit indicators 314, 315 and 316 respectively provide a visual indication of the presence of photocell sensors associated with the columns A, B and C of tape l74 respectively provide signals PCA, PCB and PCC upon detection of an opening in their respective columns. Specifically, a signal PCA from the photocell associated with the column A openings of tape 174 is indicative of the positioning of an opening in column A in alignment with the photocell and this signal is supplied to an AND gate 384 which has its other input terminal connected to receive a start signal 372 from delay multivibrator 364 (FIG. 15). A signal PCA indicative of an opening in column A in alignment with the photocell sensor is also applied to a triple input control AND gate 386 having other inputs to receive signals PCB and PCC and having an output which provides a signal ABC indicative of the presence of three aligned openings in the photocell. It should be recalled that three aligned openings in the tape are indicative that cylinder 44 has reached its maximum extended position. An invertor 388 provides a signal 390 indicative of the absence of signal ABC. An invertor 392 supplies an output signal 394 indicative of the absence of a PCA SIGNAL. The output of an AND gate is connected to a flip-flop 396 which, when activated by the output of AND gate 384, provides an A start signal 398. The other control signal input of flip-flop 396 is connected to receive a done signal 399 from a source to be discussed hereinafter.

Similarly, the photocell switch associated with column B of tape 174 provides an output signal PCB which when combined with a start signal 372 in an AND gate 400 causes a flip-flop 402 to provide a B start signal 404; Flip-flop 402 is also con-- nected to receive a done signal 399 as shown in the drawings. In like manner, the photocell associated with the C column of tape 174 provides an output signal PCC which when combined with a start signal 372 in an AND gate 406 serves to trigger a flip-flop 408 to provide a C start" signal 410.

It should also be noted that invertors 412 and 414 provide signals 416 and 418 which respectively indicate the absence of signals PCB and PCC so as to indicate that neither a hole in the B column or the C column of the tape is positioned to be sensed by the photocell readout device.

Three lifting mode control AND gates 420, 422 and 424 are provided for providing triggering signals to a triple entry OR gate 426 whose output provides an OK to lift signal 428. Specifically, AND gate 420 provides an output signal 421 upon the simultaneous receipt of start signal 398 and a signal 416 indicative of the absence of a B readout and gate 422 provides an output signal 423 upon the simultaneous receipt of a B start signal 404 and a signal 418 indicative of the absence of a C readout from the photoelectric means while AND gate 424 provides an output signal 425 upon receipt of C start signal 410 and signal 394 indicative of the absence of an A readout from. the photoelectric means. An invertor 430 is operable to provide a signal 432 indicative of the absence of an OK to lift signal 428.

Similarly, three lowering mode control AND gates 440, 442 and 444 are connected to provide an output signal to a triple entry OR gate 446 which provides an OK to lower signal 448. An invertor 449 provides a signal 450 indicative of the absence of an OK to lower signal 448. An output signal 441 from gate 440 is initiated upon the simultaneous receipt of an A start signal 398 and a signal 418 indicative of the absence of a C hole in the photoelectric readout means. Similarly, gate 442 provides an output signal 443 upon the simultaneous receipt of a B start signal 404 and a signal 394 indicative of the absence of an A hole in the photoelectric sensing means. In like manner, gate 444 provides an output signal 445 upon the receipt of simultaneous C start signal 410 and a 416 signal indicative of the absence of a B at the photoelectric sensing means.

Therefore, it will be obvious that an OK to lift signal 428 will be triggered upon actuation of any one of gates 420, 422

and 424 whereas an OK to lower signal 448 will be triggered upon actuation of either gates 440, 442 or 444.

The unit go" relay 452 is connected to a trigger amplifier 454 which is triggered by the output of an AND gate 456. Gate 456 is activated by the simultaneous receipt of a control signal 458 from an AND gate 460 and a signal 462 indicative of the absence of a fail signal (from a source to be discussed hereinafter). Gate 460 is activated upon the simultaneous receipt of a timer signal 368, a signal 464 from an OR. gate 466 and signal 370 indicative of the absence of a hold signal. Either one of two AND gates 470 or 472 can serve to trigger OR gate 466. An output signal from AND gate 470 is provided upon the simultaneous receipt of a signal 430 indicative of the absence of an OK to lift" signal 428 and a lift signal 353 whereas AND gate 472 is triggered upon the simultaneous receipt of a signal 450 indicative of the absence of an OK to lower signal 448 and a unit lower signal 376. An OR gate 474 is connected through invertors to receive signals indicative of the absence of lift or lower signals 353 or 376 to provide a triggering input 477 to OR gate 466.

A signal 458 from AND gate 460 serves to shift a cycle terminating flip-flop 474 to provide a done signal 399. Flipflop 474 is also activatable by a start" signal 372 to provide a signal 476 indicative of the absence of a done signal.

The logic circuitry most directly concerned with the actuation of each cylinder 44 is illustrated in FIG. 17. Specifically, coil 137 for directing fluid to cause a lifting operation is activated by an output signal 480 of a main lift triggering OR gate 482 which can be triggered by any one of three signals 484, 486 or 488. Signal 484 is provided by a delay multivibrator 490 which is triggered by a TPR valve signal 604 (see FIG. 19) which is the activator signal for the top pin valve control circuit 131 for causing the top pins 116 of the unit to be retracted. Signal 486, on the other hand, is an output from and AND gate 492 which must simultaneously receive a pressure signal 321, a signal 390 indicative of the absence of parallel holes A, B and C in the photoelectric readout means, a TPO signal indicative of the fact that the top pins are out, a BPR signal indicative that the bottom pins 108 are retracted to the position illustrated by the pins 108 associated with the upper slab of FIG. and a lowering mode signal 350 from flip-flop 346 (FIG. 15) so as to provide an output signal 486.

A signal 483 is provided by AND gate 494 upon the simultaneous receipt of an OK to move" signal 496, an 01K to lift signal 428 and a unit lift signal 353. The OK to move signal 496 is the output signal from an AND gate 494 which provides signal 494 upon the simultaneous receipt of a pressure signal 321, a BPO signal and a TPR signal.

Similarly, coil 135 for activating cylinder 44 to cause a lowering movement is activated by an OR gate 500 which is triggered by any one of signals 502, 504 or 506. Signal 506 is the output signal from a delay multivibrator 508 which is activated upon receipt of a BPR signal 558 which also serves to activate means 133, 132 to cause the lower pins to retract. Similarly, signal 502 is the output signal from an AND gate 510 which is activated upon the simultaneous receipt of an OK to move signal 496, an OK to lower" signal 448 and a unit lower signal 376 from OR gate 374 (FIG. 15). Signal 504 is the output signal from an AND gate 512 and is resultant from the simultaneous application of a pressure signal 321, a signal 342 indicative that the jack is not in its bottom or completely compressed condition, a TPO signal, A BPR signal and a lifting mode signal 348.

Logic circuitry for indicating a jack unit failure is illustrated in FIG. 18 and includes a fail flip-flop 514 capable of providing a fail signal 516 or the previously discussed absence of fail signal 462. A fail signal 516 is provided from flip-flop 514 upon receipt of a trigger signal 518 from an OR gate 520. OR gate 520 is triggered by receipt of any one of seven signals 521, 522, 523, 524, 525, 526 or 527.

Signal 521 is the output signal from an AND gate 528 which is activated to indicate that the unit is mispositioned upon the simultaneous receipt of a lifting signal 348, A start" signal 398 and a PCC signal. Similarly, signal 522 is resultant from the triggering of an AND gate 520 which is triggered upon the simultaneous receipt of a lifting signal 348, a B start signal 404 and a PCA signal. In like manner, signal 523 is the output signal of an AND gate 532 which is triggered upon the simultaneous receipt of a lifting signal 348, a C start signal 410 and a PCB signal.

Signals 524, 525 and 526 are indicative of failure during lowering mode of operation. Specifically, signal 524 is provided by the output of an AND gate 534 which is activated upon the simultaneous receipt of a lowering signal 350, a B start signal 404 and a PCC signal indicative of the presence of a C column opening in the photoelectric readout means. Signal 526 is produced by the output of an AND gate 538 which is activated upon the simultaneous receipt of a lowering signal 350, a C start" signal 410 and a PCA signal indicative of the presence of a column A opening in the readout means.

Signal 527, on the other hand, is an output signal from AND gate 540 which is activated upon the simultaneous receipt of a signal 476 indicative of the absence of a done signal and an output signal 542 from a delay multivibrator 544. Delay multivibrator 544 is activated by the output of another delay multivibrator 546 which is activated by timer signal 368.

FIG. 19 illustrates the control and logic system for controlling the hydraulic means for activating the upper pins 116 and the lower pins 108. A system hold flip-flop 548 provides a hold signal 549 at the termination of either a lifting or lowering jack operation for the purpose of maintaining the system until the next cycle. Hold signal 549 is initiated upon receipt of a command from an OR gate 550, which, in turn, is activated upon receipt of a signal from a lifting cycle termination AND gate 552 or a lowering cycle termination AND gate 554. The lifting cycle terminating AND gate 552 is activated upon the simultaneous receipt of a signal ABC indicative of the presence of three aligned openings in the photocell readout means and a lifting signal 348. Similarly, the lowering cycle terminating AND gate 554 provides an output signal upon the simultaneous receipt of a bottom signal 338 indicative that the cylinder unit 4 has reached the maximum compressed stage and a lowering signal 350.

Signal 370 indicative of the absence of a hold signal is provided from flip-flop S48 upon receipt of a signal 556 indicative of the absence of a valve control signal 558, which activates the bottom pin valve 132 to retract the bottom pins. Signal 556 is provided from a delay multivibrator 560 which is activated by an invertor 561. The signal 558 for retracting the bottom pins is the output from an AND gate 562 which is activated in response to the simultaneous receipt of a TPO signal indicative that the top pins are out or extended, a hold signal 549 and an operating signal 564 from an OR gate 566. Gate 566 is activated upon the receipt of an output signal from an AND gate 600 or from an AND gate 602. The AND gate 600 is activated in response to the simultaneous receipt of a signal 342 indicative of the absence of a bottom signal and a lifting signal 348. Similarly, AND- gate 602 is activated upon receipt of a signal 390 indicative of the absence of an ABC signal and a lowering signal 350. The electromagnetic valve 130 for controlling the top pins 116 is activated to retract the pins by the top pin retracting signal 604 supplied to control 131 from the output of an AND gate 606. Signal 604 is provided in response to simultaneous receipt of a pressure signal 321, a signal 468 indicative of the absence of a hold condition and a BPO signal indicating that the bottom pins are extended.

A cycle of operation (in this instance a lifting cycle) begins with the operator adjusting counter 274 (FIG. 14) to set the distance it is desired to lift the top slab. The main power supply is then activated to provide current to line 202 and control signal current source 238 is also activated. Power from line 210 immediately activates the pump motors 120 of each jack unit to provide the hydraulic pressure necessary for controlling and activating the jack units. Consequently, assuming that all of the pumps are functioning properly, switch 320 is closed to provide a pressure signal 321. If the counter has a count greater than zero registered in it, the indicator lamp 251 will be activated and the operator will reset the counter by depressing the manual reset switch 282. For this example, it will be assumed that only one slab will be lifted and that the control circuitry for that particular slab is the circuitry illustrated in the drawings. The switch 216 for providing artificial go" signals from the other slabs will be closed, so that it will be necessary to receive a go signal only from the slab to be moved.

The following discussion will be limited to the controls for only one jack unit although it should be understood that all jack units of the slab are activated at the same time.

A typical lifting cycle of operation begins with the operator closing lift switch 236 of the main console 200 (FIG. 14) which remains closed for a short period of time as shown in the timing chart of FIG. 20. Closure of switch 236 at t immediately initiates a lift mode signal 250 from flip-flop 239 which, in turn, when combined with signal 268 in AND gate 264, results in a lift signal 206 being applied to each jack unit of the slab to be moved as will be obvious from FIG. 14 to which attention is directed. The lift signal on line 206 is simultaneously applied to flip-flop and OR gate 352 to provide a lifting signal and a unit lift signal 353. Unit lift signal 353 triggers OR gate 360. The output signal from OR gate 360 starts first and second delay multivibrators 362 and 364 and the timer output signal 368 is terminated to remain deactivated for a given period of time at t The delay multivibrator 364 immediately provides a start signal pulse 372 at t The termination of timer signal 368 at I, immediately terminates the output from gate 460 (FIG. 16) so that go relay 452 goes off and done signal 399 terminates simultaneously at t,. Termination of the activation of go relay 452 immediately drops the all go signal 215 from gate 214.

At the beginning of a lifting operation, the metal tape is positioned so that hole A is positioned in the photoelectric readout means to provide a signal PCA. Signal PCA is combined with start signal 372 at t, to give an A start signal 398 from flip-flop 396. Signal 398 is combined in AND gate 420 with signal 416 indicative that the B column hole is not being detected in the photoelectric means (assuming that the system is functioning correctly) and a resultant signal 421 triggers OR gate 426 to give an OK to lift signal 428 at 1,.

It should be noted that start signal 372 is of short duration and is terminated at t however, the signal 398 from flip-tlop 396 does not terminate with the tennination of the start signal. The lift valve solenoid 137 is also activated by signal 480 at t to initiate operation of cylinder 44 to begin the lifting movement of the slab. As the slab is lifted upwardly, the hole in column A will cease to be detected by the photoelectric means so that signal PCA will drop out; however, flip-flop 396 remains set and A start" signal 398 does not drop out at this time. Solenoid 137 will remain activated by the output from OR gate 482 which remains triggered. However, the lifting movement of the slab eventually results in detection of hole B in the control tape so as to provide a signal PCB at t;,. The OK to lift signal 428 is immediately terminated at by virtue of the termination of the negative B signal 416 which terminates the output of gate 420 which, in turn, terminates the OK to lift signal 428 from gate 420 upon detection of the B opening at 1 Lift valve solenoid 137 is deactivated at t; by virtue of the termination of the OK to lift signal 428 which terminates the output 488 from AND gate 494 as shown in FIG. 17.

The timer signal 368 automatically returns at t, after a time period sufficient for allowing all jack units to have completed an increment of movement has elapsed in accordance with the time delay factor designed into delay multivibrator 362. All jacks must have completed their l-inch increment of movement during the time interval that the timer signal was not being supplied (t -t Initiation of the timer signal 368 at t, immediately results in the simultaneous termination of the A start signal 398 by virtue of the timer signals activation of gate 460 (FIG. 16) which initiates a done signal from flip-flop 474 which, in turn, terminates the output 398 from flip-flop 396. If all of the jacks have functioned properly to make one increment of movement, (as evidenced by signal 370 at gate 460) a "go signal will simultaneously be provided by relay 452 at When all of the go relays of the slab have been activated, the master AND gate 214 (FIG. 14) will provide an all go signal 215 to delay multivibrator 270 to provide a stepcompleted signal 272 at The step-completed signal 272 in combination with the lift mode signal 250 activates the count up AND gate 300 to add one count to counter 274. If the count in the counter should equal the preset valve in the counter, a system stop signal 278 would be provided to gate 260 for deactivation of the system.

However, assuming that the preset count has not been reached, the system then proceeds to initiate the next increment of movement (from B to C). It should be noted that the system lift signal 206 from gate 264 (FIG. 14) is terminated at t; by the termination of signal 268 indicative of the activation of delay multivibrator 270 by all go signal 215.

Signal 268 is reinitiated at 1 and immediately results in the initiation of another system lift signal 206 at t from gate 264 which results in a simultaneous start signal 372 from delay multivibrator 364 at Since the tape is now in the B readout position, start signal 372 is combined with photocell signals PCB (FIG. 16) to provide a B start signal 404 at t.;. Lift valve solenoid 137 is also activated at this time to initiate another increment of lifting movement of the cylinder assembly 44 in the same manner as occurred at t Also, done signal 399 and signal 455 for the go relay are both terminated at t while the OK to lift signal 428 is initiated at this time along with timer signal 368. The operation continues in the same manner as the slab is lifted to the C position.

The incremental lifting cycles continue until the counter reaches its preset value or the cylinder assembly 44 is fully extended as indicated by the detection of an ABC signal. The detection of an ABC signal initiates the recycling of the jack to its compressed or contracted condition so that another lifting cycle can begin. FIG. 21 illustrates the timing of such a recycling movement which begins at 1, with the simultaneous detection of horizontally aligned holes A, B and C in the control tape.

Turning now to FIG. 19, it will be seen that the concurrent receipt of signal ABC and lifting signal 348 at AND gate 552 will trigger OR gate 550 which, in turn, triggers flip-flop 548 to provide a hold signal 549 at 1, The lift valve solenoid 137 is simultaneously deactivated and the OK to lift" signal 428 is terminated at t The signal 604 for retracting the top pins is terminated at r by the dropping out of signal 468 at gate 606 so that the top pins control valve is shifted to cause the pins to extend outwardly through the openings in the flange of the beam and the upper lift bars 66 with which the pins are associated. This movement requires a small period of time and is completed at t as indicated by signal TPO which triggers gate 562 to give a bottom pins retract control signal 558. A shortduration valve lower signal 501 is triggered by a short pulse from delay multivibrator 508 which is activated by signal 558 at to lessen the force on the bottom pins and enable retraction of the bottom pins without undue effort. It is noted that the timing chart of FIG. 21 does not make any provision for a time period between signals TPR and TPO while it is obvious that there would actually be a small time period during which neither the retracted position sensing switches 172 and 172 and the extended position switches and 170' would be 1 closed (activated). However, this time period is of short duration and is not shown since the condition existent during the time period has no effect on the other circuit elements and its inclusion would merely complicate the timing chart. Similarly, the switches associated with the lower pins also operate in the same manner and are illustrated as being activated and deactivated simultaneously while such actually is not the case. The short-duration lower valve control signal terminates at and a new timer signal 368 is initiated at t A primary lower valve control signal 501 is initiated by gate 512 at I to cause cylinder 44 to begin a new lowering operation (contraction of the piston and cylinder assembly) until time r at which time the cylinder and piston assembly is completely compressed to provide a bottom signal 338 indicative of such condition. The bottom signal 338 immediately causes termination of signal 342 to AND gate 512 so as to discontinue the lowering signal 501 to solenoid 135. The termination of movement at t also coincides with detection of an opening in the A column of holes and tape 174 as evidenced by signal PCA.

Simultaneously, a go signal is provided to AND gate 214 and a done" signal is also initiated. Hold signal 549 is terminated at r A short-duration lift signal 480 is applied to the control valve for the cylinder 44 at to enable a retraction of the top pins. It should also be noted that the bottom pin retracting control signal element 133 is deactivated at t so that the bottom pins move to its other extended position in a BPO signal at Extension of the bottom pins outward into the holes in the beam enables the subsequent retraction of the top pins at t for the beginning of another lifting cycle in the manner previously discussed.

It should be noted that the control system provides failure detecting means for deactivating the system and advising the operator of any failure. Turning now to FIG. 18, it will be seen that a fail signal will be provided in the event of several occurrences which indicate an improper actuation of the lifting assembly. For example, AND gate 528 will be activated to provide a fail signal from flip-flop 514 upon the simultaneous detection of a lifting signal 348, an A start" signal 398 and a signal PCC from the photocell readout means. This occurrence would indicate that the slab had actually lowered and moved in the wrong direction when it should have been lifting. Also, fail signal will be provided from AND gate 540 if the necessary total movement of the slab has not been accomplished in a desired time period. Flip-flop 514 can be manually reset by switch 515 as shown in FIG. 18 so as to provide signal 462. The primary significance of the fail signal is that its presence indicates that there can be no signal 462 indicative of the absence of a fail and consequently no go" signal can be provided from the go relay for the particular jack unit.

A lowering slab operation is accomplished in the same manner as the lifting operation with the exception that the lowering circuitry control elements are activated instead of the lifting circuit control elements. It should be understood that the control logic circuitry elements can assume a wide variety of forms for performing the desired logic functions.

Moreover, the system components can be varied in accordance with the specific construction being performed and the subject invention obviously is not limited to building construction in that it can be used in the construction of bridges, piers, docks and other types of constructions. Similarly, the slabs lifted by the system are not limited to concrete and could obviously employ other materials, such as wood, steel, etc. Therefore, it should be clearly understood that the foregoing relates solely to the preferred embodiment of this invention and the scope of the invention should be determined solely by the following claims.

We claim:

1. A lifting system for enabling the lifting of a concrete slab upward along a plurality of vertical H-beams having a series of horizontally extending openings arranged vertically along their length in the form of a vertical row of openings on opposite sides of each flange of said beam, said lifting system comprising a plurality of jack units connected to said slab adjacent each beam with each jack unit including a vertically extendable and contractable power means including first and second vertical hydraulic piston and cylinder assemblies located on opposite sides of said beam, and upper lifting frame and a lower lifting frame respectively connected to the upper end and lower end of said extendable and contractable power means, horizontally movable upper pin means mounted on said upper lifting frame, said upper pin means comprising two pairs of pins with each pair respectively located on said opposite sides of said beam, horizontally movable lower pin means mounted on said lower lifting frame, said lower pin means also comprising two pairs of pins with each pair respectively located on said opposite sides of said beam, wherein each of the pins of each pair move in opposite directions when moved to their extended positions, upper power actuated drive means for selectively moving said upper pin means to either an extended position in which said upper pin means is received in one of said openings in said beam or a retracted position in which said upper pin means is completely retracted from engagement with said opening in said beam to permit vertical movement of said upper lifting frame either upwardly or downwardly with respect to said beam upon actuation of said vertically extendable and contractable power means, lower power actuated drive means for selectively moving said lower pin means to either an extended position in which said lower pin means is received within said opening in said beam or a retracted position in which said lower pin means is completely retracted from engagement with said openings in said beam to permit vertical movement of said lower lifting frame either upwardly or downwardly with respect to said beam, means connecting said upper lifting frame to said concrete slab so that movement of said power means to its extended position when said upper pin means is in its retracted position and said lower pin means is in its extended position serves to vertically lift said slab.

2. The system of claim 1 wherein said upper drive means and said lower drive means respectively consist of two pairs of hydraulic piston and cylinder assemblies with each pair being respectively located on opposite sides of said web.

3. The system of claim 2 additionally including a hydraulic pump means for providing pressurized fluid to said hydraulic piston and cylinder assemblies and an electric motor for driving said hydraulic pump, said hydraulic pump means being attached to said lower lifting frame.

4. A lifting system for enabling the lifting of a concrete slab upward along a plurality of vertical beams having a series of horizontally extending openings along their length, said lifting system comprising a plurality of jack units connected to each slab adjacent each beam with each jack unit including a vertically extendable and contractable power means, an upper lifting frame and a lower lifting frame respectively connected to the upper and lower end of said extendable and contractable power means, horizontally movable upper pin means mounted on said upper lifting frame, a horizontally movable lower pin means mounted on said lower lifting frame, upper power actuated drive means for selectively moving said upper pin means to either an extended position in which said upper pin means is received in one of said openings in said beam or a retracted position in which said upper pin means is completely retracted from engagement with said opening in said beam to permit vertical movement of aid upper lifting frame either upwardly or downwardly with respect to said beam upon actuation of said vertically extendable and contractable power means, lower power actuated drive means for selectively moving said lower pin means to either an extended position in which said lower pin means is received within said openings in said beam or a retracted position in which said lower pin means is completely retracted from engagement with said openings in said beam to permit vertical movement of said lower lifting frame either upwardly or downwardly with respect to said beam, means connecting said upper lifting frame to said concrete slab so that movement of said power means to its extended position when said upper pin means is in its retracted position and said lower pin means is in its extended position serves to vertically lift said slab and control means for activating said extendable and contractable power means, said lower drive means and said upper drive means in timed relationship with respect to each other so that said slab is cyclically walked along said beams wherein said control means also includes means for detecting malfunction of any of said jack units to deactivate all of said units in response to detection of a malfunction of any jack unit.

5. The system of claim 4 wherein said control means includes means connected between said upper lifting frame and said lower lifting frame for providing spacing signals indicative of the distance between said upper lifting frames and said lower lifting frames and means responsive to said spacing signals for deactivating the vertical hydraulic piston and cylinder assemblies extending between said frames in response to the positioning of said frames in a position in which said frames are a predetermined distance apart.

6. The system of claim 4 wherein said control means includes a main console connected to each jack unit by control and power cables so as to provide centralized control of each jack unit.

7. The system of claim 6 wherein said power means includes first and second vertical hydraulic piston and cylinder assemblies located on opposite sides of said beam.

8. The system of claim 7 wherein said upper pin means comprises two pairs of pins with each pair respectively located on said opposite sides of said beam and said lower pin means also comprises two pairs of pins with each pair respectively located on said opposite sides of said beam.

9. The system of claim 8 wherein each of the pins of each pair move in opposite directions when moved to their extended positions.

10. The system of claim 9 wherein said beam is an H-beam and said vertically extending openings are in the form of a vertical row of openings on opposite sides of each flange of said beam.

11. The system of claim 10 wherein said upper drive means and said lower drive means respectively consist of two pairs of hydraulic piston and cylinder assemblies with each pair being respectively located on opposite sides of said web.

12. The system of claim 11 additionally including a hydraulic pump means for providing pressurized fluid to said hydraulic piston and cylinder assemblies and an electric motor for driving said hydraulic pump, said hydraulic pump means being attached to said lower lifting frame.

13. The system of claim 6 wherein said control means include means for simultaneously activating all of said extendable and contractable means for incremental movement of said upper lifting frame upwardly away from said lower frame to a fully extended position in which said upper lifting frame and said lower lifting frame are spaced apart a maximum possible distance and means for detecting said fully extended position to initially activate said upper drive means to move said upper pins to their extended position and to subsequently activate said lower drive means to move said lower pins to said lower pins retracted position and to subsequently activate said extendable and contractable power means to cause said power means to contract to the fullest extent possible to enable a subsequent movement of the lower pins to their extended position and retraction of the upper pins to their retracted position so that the power means can again be activated to move to its extended position to initiate another cycle of operation.

14. The system of claim 13 wherein said control means includes a settable counter which receives count signals each of which is indicative that all of sad jack units have moved a set increment of movement and for providing a system stop signal upon reaching a preset count indicative that the upper lifting frame has moved a required distance to deactivate said system so that there is no further movement of the upper lift frame.

15. The system of claim 14 wherein said control means additionally includes means for detecting the failure of any one of said jack units to move an increment of movement within a predetermined period of time so as to provide a fail signal at said console.

16. A lifting system for enabling the lifting of a concrete slab upward along a plurality of vertical beams having a series of vertically extending openings along their length, said lifting system comprising a plurality of jack units connected to said slab adjacent each beam with each jack unit including a vertically extendable and contractable power means, an upper lifting frame and a lower lifting frame respectively connected to the upper end and lower end of said extendable and contractable power means, horizontally movable upper pin means mounted on said upper lifting frame, horizontally movable lower pin means mounted on said lower lifting frame, upper drive means for moving said upper pin means between an extended position in which said upper pin means is received in one of said openings in said beam and a retracted position in which said upper pin means is completely retracted from engagement with said opening in said beam to permit vertical movement of said upper lifting frame with respect to said beam upon actuation of said vertically extendable and contractable power means, lower drive means for moving said lower pin means between an extended position in which said lower pin means is received within said opening in said beam and a retracted position in which said lower pin means is completely retracted from engagement with said openings in said beam to permit vertical movement of said lower lifting frame with respect to said beam, means connecting said upper lifting frame to said concrete slab, said means connecting said upper lifting frame to said concrete slab including a lift ring assembly embedded in the slab and encircling each beam and associated jack means so that movement of said power means to its extended position when said upper pin means is in its retracted position and said lower pin means is in its extended position serves to vertically lift said slab and control means for activating said extendable and contractable power means, said lower drive means and said upper drive means in timed relationship with respect to each other so that said slab is cyclically walked along said beams.

17. The invention of claim 16 wherein each lift ring assembly is of sufficient diameter as to enable the vertical removal of said jack unit from operative relationship with said ring assembly and said beam so that a permanent attachment of said beam and said slab can be effected subsequently and said jack unit will be available for future use.

18. The invention of claim 17 wherein said ring assembly isprovided with an inner surface facingly encircling said beam and having a cross-sectional shape of arcuate configuration and a plurality of lift blocks having outer surfaces of a mating arcuate configuration with respect to said inner surface which are biassed against'said inner surface by means connected between said upper frame and said lift blocks. v

19 A lifting system for enabling the lifting of a concrete slab upward along a plurality of vertical beams having a series of vertically extending openings along their length, said lifting system comprising a plurality of jack units connected to said slab adjacent each beam with each jack unit including a vertically extendable and contractable power means, an upper lifting frame and a lower lifting frame respectively connected to the upper end and lower end of said extendable and contractable power means, horizontally movable upper pin means mounted on said upper lifting frame, horizontally movable lower pin means mounted on said lower lifting frame, upper drive means for moving said upper pin means between an extended position in which'said upper pin means is received in one of said openings in said beam and a retracted position in which said upper pin means is completely retracted from engagement with said opening in said beam to perrnitvertical movement of said upper lifting frame with respect to said beam upon actuation of said vertically extendable and contractable power means, wherein said upper lifting frame includes a pair of upper lift bars each of which is provided with openings alignable with said openings in said beam whereby said upper pins extend through said openings in said upper lift bars when said upper pins are in their extended position, lower drive means for moving said lower pin means between an extended position in which said lower pin means is received within said opening in said beam and a retracted position in which said lower pin means is completely retracted from engagement with said openinm in said beam to permit vertical movement of said lower lifting frame with respect to said beam, means connecting said upper lifting frame to said concrete slab so that movement of said power means to its ex? tended position when said upper pin means is in its retracted position and said lower pin means is in its extended position serves to vertically lift said slab and control means for activating said extendable and contractable power means, said lower drive means and said upper drive means in timed relationship with respect to each other so that said slab is cyclically walked are H-beams and said upper lift bars extend horizontally along.

the outer surfaces of the flanges of said H-beams and said 

1. A lifting system for enabling the lifting of a concrete slab upward along a plurality of vertical H-beams having a series of horizontally extending openings arranged vertically along their length in the form of a vertical row of openings on opposite sides of each flange of said beam, said lifting system comprising a plurality of jack units connected to said slab adjacent each beam with each jack unit including a vertically extendable and contractable power means including first and second vertical hydraulic piston and cylinder assemblies located on opposite sides of said beam, and upper lifting frame and a lower lifting frame respectively connected to the upper end and lower end of said extendable and contractable power means, horizontally movable upper pin means mounted on said upper lifting frame, said upper pin means comprising two pairs of pins with each pair respectively located on said opposite sides of said beam, horizontally movable lower pin means mounted on said lower lifting frame, said lower pin means also comprising two pairs of pins with each pair respectively located on said opposite sides of said beam, wherein each of the pins of each pair move in opposite directions when moved to their extended positions, upper power actuated drive means for selectively moving said upper pin means to either an extended position in which said upper pin means is received in one of said openings in said beam or a retracted position in which said upper pin means is completely retracted from engagement with said opening in said beam to permit vertical movement of said upper lifting frame either upwardly or downwardly with respect to said beam upon actuation of said vertically extendable and contractable power means, lower power actuated drive means for selectively moving said lower pin means to either an extended position in which said lower pin means is received within said opening in said beam or a retracted position in which said lower pin means is completely retracted from engagement with said openings in said beam to permit vertical movement of said lower lifting frame either upwardly or downwardly with respect to said beam, means connecting said upper lifting frame to said concrete slab so that movement of said power means to its extended position when said upper pin means is in its retracted position and said lower pin means is in its extended position serves to vertically lift said slab.
 2. The system of claim 1 wherein said upper drive means and said lower drive means respectively consist of two pairs of hydraulic piston and cylinder assemblies with each pair being respectively located on opposite sides of said web.
 3. The system of claim 2 additionally including a hydraulic pump means for providing pressurized fluid to said hydraulic piston and cylinder assemblies and an electric motor for driving said hydraulic pump, said hydraulic pump means being attached to said lower lifting frame.
 4. A lifting system for enabling the lifting of a concrete slab upward along a plurality of vertical beams having a series of horizontally extending openings along their length, said lifting system comprising a plurality of jack units connected to each slab adjacent each beam with each jack unit including a vertically extendable and contractable power means, an upper lifting frame and a lower lifting frame respectively connected to the upper and lower end of said extendable and contractable power means, horizontally movable upper pin means mounted on said upper lifting frame, a horizontally movable lower pin means mounted on said lower lifting frame, upper power actuated drive means for selectively moving said upper pin means to either an extended position in which said upper pin means is received in one of said openings in said beam or a retracted position in which said upper pin means is completely retracted from engagement with said opening in said beam to permit vertical movement of aid upper lifting frame either upwardly or downwardly with respect to said beam upon actuation of said vertically extendable and contractable power means, lower power actuated drive means for selectively moving said lower pin means to either an extended position in which said lower pin means is received within said openings in said beam or a retracted position in which said lower pin means is completely retracted from engagement with said openings in said beam to permit vertical movement of said lower lifting frame either upwardly or downwardly with respect to said beam, means connecting said upper lifting frame to said concrete slab so that movement of said power means to its extended position when said upper pin means is in its retracted position and said lower pin means is in its extended position serves to vertically lift said slab and control means for activating said extendable and contractable power means, said lower drive means and said upper drive means in timed relationship with respect to each other so that said slab is cyclically walked along said beams wherein said control means also includes means for detecting malfunction of any of said jack units to deactivate all of said units in response to detection of a malfunction of any jack unit.
 5. The system of claim 4 wherein said control means includes means connected between said upper lifting frame and said lower lifting frame for providing spacing signals indicative of the distance between said upper lifting frames and said lower lifting frames and means responsive to said spacing signals for deactivating the vertical hydraulic piston and cylinder assemblies extending between said frames in response to the positioning of said frames in a position in which said frames are a predetermined distance apart.
 6. The system of claim 4 wherein said control means includes a main console connected to each jack unit by control and power cables so as to provide centralized control of each jack unit.
 7. The system of claim 6 wherein said power means includes first and second vertical hydraulic piston and cylinder assemblies located on opposite sides of said beam.
 8. The system of claim 7 wherein said upper pin means comprises two pairs of pins with each pair respectively located on said opposite sides of said beam and said lower pin means also comprises two pairs of pins with each pair respectively located on said opposite sides of said beam.
 9. The system of claim 8 wherein each of the pins of each pair move in opposite directions when moved to their extended positions.
 10. The system of claim 9 wHerein said beam is an H-beam and said vertically extending openings are in the form of a vertical row of openings on opposite sides of each flange of said beam.
 11. The system of claim 10 wherein said upper drive means and said lower drive means respectively consist of two pairs of hydraulic piston and cylinder assemblies with each pair being respectively located on opposite sides of said web.
 12. The system of claim 11 additionally including a hydraulic pump means for providing pressurized fluid to said hydraulic piston and cylinder assemblies and an electric motor for driving said hydraulic pump, said hydraulic pump means being attached to said lower lifting frame.
 13. The system of claim 6 wherein said control means include means for simultaneously activating all of said extendable and contractable means for incremental movement of said upper lifting frame upwardly away from said lower frame to a fully extended position in which said upper lifting frame and said lower lifting frame are spaced apart a maximum possible distance and means for detecting said fully extended position to initially activate said upper drive means to move said upper pins to their extended position and to subsequently activate said lower drive means to move said lower pins to said lower pins'' retracted position and to subsequently activate said extendable and contractable power means to cause said power means to contract to the fullest extent possible to enable a subsequent movement of the lower pins to their extended position and retraction of the upper pins to their retracted position so that the power means can again be activated to move to its extended position to initiate another cycle of operation.
 14. The system of claim 13 wherein said control means includes a settable counter which receives count signals each of which is indicative that all of said jack units have moved a set increment of movement and for providing a system stop signal upon reaching a preset count indicative that the upper lifting frame has moved a required distance to deactivate said system so that there is no further movement of the upper lift frame.
 15. The system of claim 14 wherein said control means additionally includes means for detecting the failure of any one of said jack units to move an increment of movement within a predetermined period of time so as to provide a fail signal at said console.
 16. A lifting system for enabling the lifting of a concrete slab upward along a plurality of vertical beams having a series of vertically extending openings along their length, said lifting system comprising a plurality of jack units connected to said slab adjacent each beam with each jack unit including a vertically extendable and contractable power means, an upper lifting frame and a lower lifting frame respectively connected to the upper end and lower end of said extendable and contractable power means, horizontally movable upper pin means mounted on said upper lifting frame, horizontally movable lower pin means mounted on said lower lifting frame, upper drive means for moving said upper pin means between an extended position in which said upper pin means is received in one of said openings in said beam and a retracted position in which said upper pin means is completely retracted from engagement with said opening in said beam to permit vertical movement of said upper lifting frame with respect to said beam upon actuation of said vertically extendable and contractable power means, lower drive means for moving said lower pin means between an extended position in which said lower pin means is received within said opening in said beam and a retracted position in which said lower pin means is completely retracted from engagement with said openings in said beam to permit vertical movement of said lower lifting frame with respect to said beam, means connecting said upper lifting frame to said concrete slab, said means connecting said upper lifting frame to said concrete slab including a lift riNg assembly embedded in the slab and encircling each beam and associated jack means so that movement of said power means to its extended position when said upper pin means is in its retracted position and said lower pin means is in its extended position serves to vertically lift said slab and control means for activating said extendable and contractable power means, said lower drive means and said upper drive means in timed relationship with respect to each other so that said slab is cyclically walked along said beams.
 17. The invention of claim 16 wherein each lift ring assembly is of sufficient diameter as to enable the vertical removal of said jack unit from operative relationship with said ring assembly and said beam so that a permanent attachment of said beam and said slab can be effected subsequently and said jack unit will be available for future use.
 18. The invention of claim 17 wherein said ring assembly is provided with an inner surface facingly encircling said beam and having a cross-sectional shape of arcuate configuration and a plurality of lift blocks having outer surfaces of a mating arcuate configuration with respect to said inner surface which are biassed against said inner surface by means connected between said upper frame and said lift blocks.
 19. A lifting system for enabling the lifting of a concrete slab upward along a plurality of vertical beams having a series of vertically extending openings along their length, said lifting system comprising a plurality of jack units connected to said slab adjacent each beam with each jack unit including a vertically extendable and contractable power means, an upper lifting frame and a lower lifting frame respectively connected to the upper end and lower end of said extendable and contractable power means, horizontally movable upper pin means mounted on said upper lifting frame, horizontally movable lower pin means mounted on said lower lifting frame, upper drive means for moving said upper pin means between an extended position in which said upper pin means is received in one of said openings in said beam and a retracted position in which said upper pin means is completely retracted from engagement with said opening in said beam to permit vertical movement of said upper lifting frame with respect to said beam upon actuation of said vertically extendable and contractable power means, wherein said upper lifting frame includes a pair of upper lift bars each of which is provided with openings alignable with said openings in said beam whereby said upper pins extend through said openings in said upper lift bars when said upper pins are in their extended position, lower drive means for moving said lower pin means between an extended position in which said lower pin means is received within said opening in said beam and a retracted position in which said lower pin means is completely retracted from engagement with said openings in said beam to permit vertical movement of said lower lifting frame with respect to said beam, means connecting said upper lifting frame to said concrete slab so that movement of said power means to its extended position when said upper pin means is in its retracted position and said lower pin means is in its extended position serves to vertically lift said slab and control means for activating said extendable and contractable power means, said lower drive means and said upper drive means in timed relationship with respect to each other so that said slab is cyclically walked along said beams.
 20. The invention of claim 19 wherein said lower lifting frame includes a pair of lower lift bars each of which is provided with openings alignable with said openings in said beam whereby said lower pins extend through said openings in said lower lift bars when said lower pins are in their extended position.
 21. The invention recited in claim 20 wherein said beams are H-beams and said upper lift bars extend horizontally along the outer surfaces of the flanges of said H-beams and said lower lift bars also extend horizontally along the outer surfaces of the flanges of said beams.
 22. The invention recited in claim 21 wherein each end of said upper lift bars supportingly engages a pair of upper support plates each of which includes a portion which extends inwardly between said beam flanges with the upper end of said vertical piston and cylinder assemblies each being connected to one of said support plates.
 23. The invention of claim 22 herein each end of said lower lift bars is attached to a horizontal cylinder support plate which respectively have the lower end of one of said vertical piston and cylinder affixed thereto.
 24. The invention of claim 23 additionally including a downwardly extending vertical plate extending downwardly from said inwardly extending portion of said upper support plates with said upper drive means comprising a pair of hydraulic piston and cylinder assemblies attached to said downwardly extending vertical plate.
 25. The invention of claim 24 additionally including an upwardly extending vertical pin supporting plate extending upwardly from said cylinder support plate with said lower drive means comprising a pair of hydraulic piston and cylinder assemblies attached to said upwardly extending vertical pin supporting plate. 